Compressed-gas circuit interrupter with pressurized arcing chamber and downstream blast valve



Sept. 27, 1966 SHOJI MORIOKA 3,275,778

COMPRESSED-GAS CIRCUIT INTERRUP'I'ER WITH PRESSURIZED ARCING CHAMBER ANDDOWNSTREAM BLAST VALVE Filed July 31, 1963 2 Sheets-Sheet 1 HIGHPRESSURE GAS Sept. 27, 1966 SHOJI MORIOKA 3,275,778

COMPRESSED-GAS CIRCUIT INTERRUPTER WITH PRESSURIZED ARCING CHAMBER ANDDOWNSTREAM BLAST VALVE 2 Sheets-Sheet Filed July 31. 1965 INVENTORWITNESSES Shoji Morioko BY MM 4 W ATTORNEY United States Patent C JapanFiled July 31, 1963, Ser. No. 298,845 Claims priority, applicationJapan, Aug. 18, 1962, 37/ 35,770 8 Claims. (Cl. 200-148) This inventionrelates generally to compressed-gas circuit interrupters and, moreparticularly, to improved arcextinguishing structures therefor.

A general object of the present invention is to provide an improvedcompressed-gas circuit interrupter in which the contacts are alwaysdisposed in a high pressure region for fast arc extinction and a minimumof prestrikin-g during the closing operation of the interrupter.

Still a further object of the present invention is the provision of animproved compressed-gas circuit interrupter capable of interruptingconsiderable power and requiring only a relatively small amount ofspace.

Still a further object of the present invention is the provision of ahigh-speed compressed-gas circuit interrupter in which are extinction isachieved in a highly .eflicient manner, and in which the isolating gapbetween the separable contacts may be a minimum due to the presence ofhigh-pressure gas surrounding the contacts at all times.

It is well known to use a compressed-gas circuit interrupter utilizing ahighly efficient arc-extinguishing gas, such as sulfur hexafiuoride (SPor selenium hexafiuoride (SeF or similar gases having excellentarc-extinguishing properties. However, it has been customary heretoforeto utilize such compressed-gas circuit interrupters with adouble-pressure arrangement in which an exhaust tank is provided, andthe separable contacts are provided in a region of relatively lowpressure. As set forth in such prior art structures, there is usuallyprovided a high-pressure gas reservoir tank disposed in the immediatevicinity of the contact structure, and the arrangement is such as topermit a discharge of high-pressure gas from said gas reservoir into thearc-extinguishing chamber through an appropriately disposed nozzle,whereby an interruption of the drawn arc is achieved.

However, there arise certain disadvantages to such a type of structureas described above inasmuch as the highpressure gas reservoir chambermay require considerable space and, consequently, to accommodate such areservoir, the exhaust tank itself must be fairly large.

Additionally, in such a double-pressure type of compressed-gas circuitinterrupter the time delay necessarily encountered for the actual gasblast to reach the arc must be considered and from a recovery-voltagestandpoint, it is undesirable to permit to the space between thecontacts to be under a relatively low pressure following interruption.

To sum up the foregoing disadvantages, it is proposed in the instantinvention to provide an arc-extinguishing chamber filled with gas underhigh pressure, and to provide a downstream blast valve so that thecontacts will always be in a high-pressure region. As a result, there isno necessity for providing a low-pressure exhaust vessel in theimmediate vicinity of the arc-extinguishing chamber, and of considerableimportance is the fact that during a closing operation, prestriking isreduced to a minimum with a consequent diminution of erosion, or wearimposed upon the separable contacts.

Accordingly, it is a further object of the present invention to providean improved high-power compressed-gas 3,275,778 Patented Sept. 27, 1966circuit interrupter particularly adapted for high-voltage application,when necessary, and requiring very little space with a small amount ofcontact separation obtained by the fact that the arc-extinguishingchamber is at all times filled with gas under high pressure. Byutilizing a downstream blast valve, the supporting column for thearc-extinguishing chamber may itself be utilized as a lowpressureexhaust tank. Preferably, a suitable compressor is provided forre-compressing the exhausted gas and forcing such re-compressed gas backinto the high-pressure arcing chamber.

Further objects will readily be apparent upon reading the followingspecification taken in conjunction with the drawings in which:

FIG. 1 is a vertical sectional view taken through an improvedcompressed-gas circuit interrupter embodying features of the presentinvention, the contact structure being illustrated in the closed-circuitposition;

FIG. 2 is a view similar to that of FIG. 1, but showing the dispositionof the several parts at an intermediate point in the opening operation;

FIG. 3 is a considerably enlarged view of the blastvalve operatingmechanism;

FIG. 4 illustrates a modification of the present invention utilizing ametallic tank structure; and,

FIG. 5 fragmentarily illustrates a portion of the operating linkage forthe embodiment of the invention illustrated in FIG. 4.

Referring to the drawings, and more particularly to FIG. 1 thereof, thereference numeral 1 generally designates a compressed-gas circuitinterrupter. As shown, the compressed-gas circuit interrupter 1comprises a highpressure arcing chamber 2, a blast-valve operatingmechanism 3, a supporting structure 4, and suitable operating mechanismand compressor structure 5 at ground potential.

More specifically, as. shown, the arc-extinguishing chamber 2 comprisesan insulating outer weatherproof casing 6 having disposed at oppositeends thereof, and suitably clamped thereto, a terminal casting 7 and acooperable terminal casting 8. As shown, the casting structures 7, 8include terminal pads9, 10, to which line connectors L and L may befixedly attached.

Disposed interiorly of the arc-extinguishing structure 2 is provided arelatively stationary contact structure 11 comprising a plurality ofcircumferentially-disposed contact fingers 12 and aninteriorly-disposedarcing contact 13. As shown, the resilient circumferentially-disposedcontact fingers 12 make contacting engagement with a tubular movablecontact 14, which is biased, by a compression spring 15, to an openposition. More particularly, the movable tubular vented contact 14includes a contact extension 16 and a spring seat 17 fixedly securedthereto. The accelerating compression spring 15 seatsupon the springseat 17 at one end, and against a guide cylinder 18 at the other end,and constantly biases the movable tubular contact 14 in a circuitopening direction.

The relatively stationary and movable contacts 11, 14 are maintained incontacting closed position, as shown in FIG. 1, by a thrust linkage 20comprising a bell-crank lever 21 pivotally mounted, as at 22, on astationary shaft. One arm 21a is pivotally connected, as at 22, to afloating link 23, the right-hand end of which is pivotally connected, asat 26, to the spring support 17.

The other arm 21b is pivotally connected, as at 30, to a floating link31, the lower end of which is pivotally connected, as at 32, to .anupstanding insulating operating rod 33.

The lower end of the insulating operating rod 33 is pivotally connected,as at 34, to an operating lever 35, which, in turn, is pivotallyconnected, as at 36, to a bracket structure 37. Suitable means may beprovided to efiect counterclockwise rotation of the operating lever 35in a circuit-closing direction. As shown, such a means may include asolenoid 40 having an energizing coil 41, which may be energized in anysuitable manner by a suitable closing circuit, not shown.

In the closed-circuit position of the circuit interrupter 1, as shown inFIG. 1, the upstanding insulating operating rod 33 is latched in theclosed position against the force exerted by the accelerating spring bya latching device 44 including a latch 45, which may be actuated torelease the operating rod 33 by energizing a coil 46 associated with anarmature 47. A suitable tripping circuit, not shown, may be provided toeffect energization of the tripping coil 46.

The blast-valve mechanism 3 comprises a thrust lever 48 pivotallymounted upon a stationary shaft 49, and having a thrust pin 50, which isin alignment with a blastvalve stem 51. The blast-valve stem 51 isdirectly connected to a blast valve 52, which is biased toward a closedposition by a blast-valve compression spring 58. To effect opening ofthe blast valve 52, the bell-crank linkage 20 is rotated in acounterclockwise direction about the shaft 22 to thereby move a camportion 53 into engagement with a roller 54, which is carried by aroller lever 55, itself pivotally supported, as at 56, upon a pivot pincarried by the blast-valve lever 48. Preferably, spring means, such as acompression spring 59, surrounding a spring rod 60 is provided to biasthe roller lever 55 in an operative clockwise direction about itspivotal support 56.

It will, therefore, be apparent that during counterclockwise rotativemovement of the bell-crank lever 20, the cam portion 53 will cam theblast-valve lever 48 in a clockwise direction about the shaft 49, andeffect thereby opening movement of the downstream blast valve againstthe opposition afforded by the blast-valve closing spring. On the otherhand, during a closing operation, the cam portion 53 of the bell-cranklever 21 will rotate the roller lever 55 to an inoperative positionabout its pivotal support 56, and thereby cause the blast valve toremain closed during such a closing operation.

A blast manifold structure 19 guides the gas flow through the ventedmovable contact 14 and, in addition, assists in the reciprocal guidingmotion of the movable contact 14.

The opening operation of the improved compressedgas circuit interrupter1 of the instant invention will now be described. To eflect an openingoperation, suitable means, not shown, elfect energization of thetripping solenoid 46. This will cause release of the latch 44, andthereby permit the compression spring 15 to effect opening movement ofthe movable contact 14. Simultaneously, or at a desired timerelationship therewith, the blast valve will be forced open by the camaction exerted by the cam portion 53, so that high-pressure .gas 55,such as sulfur hexafluoride (SP gas, will pass through openings 60,associated with an orifice structure 61, and pass interiorly within theregion 63 of movable contact 14 to carry the arc terminal 70 therein, asshown more clearly in FIG. 2 of the drawings. Because of the opening ofthe downstream blast-valve the gas flow will pass in the directionindicated by the arrows 73, and will pass through a cooling structure 75to be collected within the interior 78 of the upstanding supportingcolumn 79. If desired, an additional collecting tank 80 may be providedat the lower end of the supporting column 79, and a suitable compressor35 associated therewith to effect re-compression of the exhausted gas.If, for certain applications, the upstanding insulating column 79 itselfis of adequate volume, there will be no necessity for providing theadditional storage volume 80 in the supporting base of the circuitinterrupter 1.

It is to be clearly understood that the present invention is notconfined solely to an arrangement in which the arc-extinguishing chamberis made of an insulating material, such as the casing member 6. Forexample, FIG. 4 illustrates a modification of the invention involving ametallic high-pressure tank having extending therewithin terminalbushings 91, 92 carrying stationary contact structures 11 adjacent theirinner ends. Suitable terminals 94, 95 may be provided at the extremitiesof the terminal bushings 91, 92 respectively to carry the controlledcircuit L L The metallic high-pressure storage tank 90 is preferablysupported up in the .air an adequate distance above ground potential bya supporting insulating column 98, which preferably carries a feed tube,not shown, and an insulating rod structure, which performs the functionsof the insulating operating rod 33 hereinbefore described.

Cooperable with the two stationary contacts structures 11 are a pair ofmovable contact structures 14, which may be of the type hereinbeforedescribed, and associated with a blast-valve supporting and guidestructure, such as previously described. The operation of the device of'FIG. 4 is identical to that previously described with the exceptionthat two serially-related contact structures are provided.

FIG. 5 more clearly shows a portion of the movable contact operatinglinkage for the double-break compressed-gas interrupter of FIG. 4. Asshown in FIG. 5, the two movable contact extensions 16, 16, having thespring seats 17, 17', are pivotally connected by lines 27, 27 to a pairof bell-cranks 20, 20' pivotally mounted upon a common stationarysupport shaft 22. The lower arms of the bell-cranks 20, 20 are linked,as shown, to the common upstanding insulating operating rod 33 extendingupwardly interiorly of the hollow supporting column 98 It will beobvious that upward unlatching movement of the operating rod 33 willpermit the two accelerating springs 15 to force the two movable contacts14 in the opening direction toward each other, as viewed in FIG. 4. In asimilar manner, downward closing movement of the operating rod 33 willforce the two movable contacts 14 outwardly, as viewed in FIG. 4, intoclosing engagement with the stationary contacts 11.

From the foregoing description, it will be apparent that there isprovided an improved compressed-gas circuit interrupter of minimumdimensions and utilizing a pair of separable contacts constantlydisposed in a high-pressure region. For effecting rapid arc-extinction,a downstream blast valve is provided, which, in conjunction withsuitable orifice and gas-flow directing structure, is effective forrapid and eificient arc-extinction. During the closing operation,prestriking is reduced to a minimum by the fact that high-pressure gasis adjacent the separable contact structure.

Although there have been illustrated and described specific structures,it is to be clearly understood that the same were merely for the purposeof illustration, and that changes and modifications may readily beprovided therein by those skilled in the art, without departing from thespirit and scope of the invention.

I claim as my invention:

'1. In a compressed-gas circuit interrupter, in combination, meansdefining an arcing chamber containing gas under high pressure, separablecontact means including a movable venting tubular contact disposedtherein and separable to establish an are, means defining a downstreamblast-valve for venting the arcing chamber through said movable ventingtubular contact, unrestricted p assage means connecting the interior ofsaid pressurized arcing chamber through said movable venting tubularcontact with said downstream blast-valve, and means synchronizingopening of the downstream blast-valve with separation of the separablecontact structure whereby an immediate flow of high pressure gas throughthe movable venting tubular contact occurs prior to contact part.

2. The combination set forth in claim 1, wherein a supporting column isutilized to support the high-pressure arcing chamber up in the air anadequate distance above ground potential.

3. The combination according to claim 1, wherein spring means biases themovable contact means toward the open position, and bell-crank means areprovided to effect release of said spring means and compression thereofduring the closing operation.

4. The combination according to claim 3, wherein cam means areassociated with the bell-crank means for etfecting the opening of saiddownstream blast-valve means.

5. A compressed-gas circuit interrupter including upstanding insulatinghollow column means, a pressurized arcing chamber supported up in theair by said hollow column means, contact means disposed interiorly ofsaid pressurized arcing chamber and separable to establish an arc, saidcontact means including a tubular movable contact, means providing adownstream blast-valve operable to exhaust pressure into said hollowcolumn means through scaid tubular movable contact, unrestricted passagemeans connecting the interior of said pressurized arcing chamber throughsaid movable venting tubular contact with said downstream blast-valve,and gas-flow guide means for directing the exhausted gas to flow throughsaid tubular movable contact upon actuation of said downstreamblast-valve whereby an immediate flow of high pressure gas through themovable venting tubular contact occurs prior to contact part.

6. The combination according to claim 5, wherein accelerating springmeans is employed to bias the contact means to the open-circuitposition, and thrust means including a crank device is effective tomaintain the contact means closed despite the opposition afforded bysaid accelerating spring means.

- tion including a pressurized chamber having an exhaust manifoldstructure, a pair of separable contacts disposed Within said pressurizedchamber at least one of which is a movable tubular venting contact andguided for reciprocal opening and closing movement by said exhaustmanifold structure, means defining .a downstream blastvalve associatedwith said manifold structure, unrestricted passage means connecting theinterior of said pressurized chamber through said vented contact withsaid downstream blast-valve, and means synchronizing the separation ofsaid contacts with opening of the blast-valve, whereby the gas from thepressurized chamber is exhausted through the vented contact to effectarc-extinction, whereby an immediate flow of high pressure gas throughthe movable venting tubular contact occurs prior to contact part.

References Cited by the Examiner UNITED STATES PATENTS 2,454,586 11/1948 Amer 200-148 2,568,008 9/1951 Jansson 200-148 3,154,658 10/ 1964,Colclaser et a1. 200-448 3,167,630 1/ 1965 Alderman et al 200-445 ROBERTK. SC-HA EFER, Primary Examiner.

ROBERT S. MACON, KATHLEEN H. CLAFFY,

Examiners.

P. E. CRAWFORD, Assistant Examiner.

1. IN A COMPRESSED-GAS CIRCUIT INTERRUPTER, IN COMBINATION, MEANSDEFINING AN ARCING CHAMBER CONTAINING GAS UNDER HIGH PRESSURE, SEPARABLECONTACT MEANS INCLUDING A MOVABLE VENTING TUBULAR CONTACT DISPOSEDTHEREIN AND SEPARABLE TO ESTABLISH AN ARC, MEANS DEFINING A DOWNSTREAMBLAST-VALVE FOR VENTING THE ARCING CHAMBER THROUGH SAID MOVABLE VENTINGTUBULAR CONTACT, UNRESTRICTED PASSAGE MEANS CONNECTING THE INTERIOR OFSAID PRESSURIZED ARCING CHAMBER THROUGH SAID MOVABLE VENTING TUBULARCONTACT WITH SAID DOWNSTREAM BLAST-VALVE, AND MEANS SYNCHRONIZINGOPENING OF THE DOWNSTREAM BLAST-VALVE WITH SEPARATION OF THE SEPARABLECONTACT STRUCTURE WHEREBY AN IMME-